#!/usr/bin/env bash  
a="123backup" 
                          
if [[ "$a" == ^[a-z]* ]];   
then                       
    echo "$a"              
else                       
    echo "no"              
fi

array_name=(1 2 3 4)
value=${array_name[*]}
echo "${value}"

length=${#array_name[*]}
echo "${length}"

echo "传递的参数个数为:$#"
echo "第一个参数为:$1"
